Corona-discharge electrode mounting device

ABSTRACT

A tool for securing corona-discharge electrode wires, preferably of a polygonal concave (i.e. clutch) profile, wherein a wedge is driven into an opening in an electrode-support frame into which the electrode wire is inserted. The tool has a projection received within the concavity of the electrode wire and, in turn, is formed with a groove receiving the head of the wedge; the lower end of the tool is bent at an obtuse angle so that the impact portion of the tool is turned away from the electrode or any imaginary extension thereof. A pneumatic or electromotive impactor may be provided at the end of the tool remote from the wedge-engaging end.

United States Patent. [1 1 Keserin Dec. 4, 1973 [54] CORONA-DISCHARGE ELECTRODE 2,369,021 2/1945 Cloney 145/46- MOUNTING DEVICE 2,485,992 10/1949 Terry 29/203 H 3,177,952 4/1965 West 29/275 X [75] Inventor: Ivan Keserin, l-lochst, Germany [73] Assignee: Metallgesellschaft Aktiengesellschaft, Primary Examiner-Othell M. Simpson Frankfurt am Main, Germany Assistant ExaminerJ. C. Peters 22 Filed: Dec. 27, 1971 Ross Appl. No.: 212,299

[5 7] ABSTRACT A tool for securing corona-discharge electrode wires, preferably of a polygonal concave (i.e. clutch) profile, wherein a wedge is driven into an opening in an electrode-support frame into which the electrode wire is inserted. The tool has a projection received within the concavity of the electrode wire and, in turn, is formed with a groove receiving the head of the wedge; the lower end of the tool is bent at an obtuse angle so that the impact portion of the tool is turned away from the electrode or any imaginary extension thereof. A pneumatic or electromotive impactor may be provided at the end of the tool remote from the wedge-engaging end.

3 Claims, 5 Drawing Figures NEi/mmc c2 ELECTRIC HAM CORONA-DISCHARGE ELECTRODE MOUNTING DEVICE FIELD OF THE INVENTION My present invention relates to systems for mounting corona-discharge electrodes in electrode support frames or holders and, more particularly, to a tool for driving an electro-de-retaining wedge, and to an electro-de-securing assembly comprising a wedge andits setting means.

BACKGROUND OF THE INVENTION In electrostatic precipitators and the like, see for example the commonly assigned copending application Ser. No. 176,524, filed Aug. 31, 1971 a frame or other support structure receives a generally planar array of transversely spaced but mutually parallel coronadischarge electrode wires, the array being flanked by'a pair of collecting electrodes upon which the dust and other solid particles may accumulate. These accumulations are shed by the collector electrodes as a'result' of rapping, the solids accumulating in a dust-collection bin beneath the collector electrodes. The apparatus may also include blowers or the like for inducting the flow of the particle-containing gas through the space between the collector electrodes and along the array of corona-discharge electrodes. As a result'of the ionization imparted to the gaseous environment around the corona-discharge electrodes, the solid particles entrained by the gas stream become charged and are attracted electro-statically to the collector electrodes. Such systems are among the most efficient for removal of particles from a gas stream and have application in the cleaning of industrial or chemical-plant gases, the purification of air to be admitted to a dust-free space, the removal of particles from the exhaust gases of incinerators and the like, and wherever particle removal is desirable. The apparatus may be used downstream of a particle-separating device such as a cyclone, performing a coarse removal of particles by sedimentation or kinetic principles, and may be followed by a mechanical filter if desired.

Corona-discharge electrodes of many types have been described in the art and the present invention is concerned with those corona-discharge electrodes which may be termed electrode wires. Such electrode wires may have a variety of profiles, it being understood that discharge efficiency increases with the number of edges which are provided along the periphery of the electrode. Hence it is a common practice to use electrode wires having polygonal profiles and to in-- crease the sharpness of the edges by forming the sides of the polygon as concavities.

Among the securing systems which have beenproposed, those of greatest interest to the present case make use of wedges which are driven into the opening of the electrode frame after the wire has been threaded into the opening. To secure the wedge in place, it has been proposed to bendover or clench the small end of the wedge or to provide the wedge with undulations, grooves or the like in the transverse direction.

One of the major problems encountered in this regard, has been found with corona-discharge wiresof a star-shaped profile with four concave sides defining. four edges at the vertices of a rectangle or square. The sides of the profile of the star wire are approximately 4 6 mm in length and the wedge which isdriven into the gap between one of these sides and the frame, may

have a circular cross-section with a diameter of 4 6 mm in the region of the head of the wedge. Because of the small *size of the head, it is difficult to drive the wedge, whose curvature closely approximates that of the concave side of the electrode'wire to ensure close contact. when one uses a hammer or the like directly to drive such wedges, the procedure often leads to damage of the corona-discharge electrode wire. The interposition of a chisel between'the hammer and the wedge also is unsatisfactory because of possible slippage. It is also impossible to avoid-damage to the coron'a-discharge wire because of the resiliency of the chisel and canting or slippage thereof. In practice, it has been found that a uniform tensioning and anchoring of the OBJECTS OF THE INVENTION It is the principal object of the present invention to provide an improved device or tool for setting the wedges of a star-profile corona-discharge electrode whereby the aforementioned disadvantages may be obviate'd.

Still another object of the invention is to provide a system for anchoring corona-discharge electrode wires in which the effort of the worker can be reduced, the danger of damaging the wire is limited, the wires may be anchored more uniformly, and the anchoring operation can be carried out relatively speedily.

SUMMARY OF THE INVENTION These objects and others which will become apparent hereinafter, are attained, in accordance with the present invention, with the aid of a rod-shaped impact tool,

for setting the wedge of an electrode-retaining means, in'which the impact member is bent to an obtuse angle along an are over the lower one third of its length and, at its lower end, is provided with a groove facing the corona-discharge wire and dimensioned to receive the head of the wedge, the length of this groove being equal to the maximum height by which the head of the wedge can be permitted to stand above the support frame in whichit is inserted. Set back from the lower end of the tool and at the end of this recess or groove, there is provided an abutment or shoulder perpendicular to the tool axis and engageable with the upper surface of the wedge. Furthermore, the lower end of the tool above the shoulder may be formed with an arcuate ridge of a configuration complementary to that of the electrode wire and receivable in the channel or flute provided by a recessed face thereof for alignment of the tool with the wedge. The wedge,- in turn, is complementarily received within the recess of the electrode wire.

The advantage of a tool of this type resides in the fact that the wedge has its'head partly received in the channel form'ed'by a recessed face of the corona-discharge wire and cannot be engaged by a hammer or chisel. The abutment surface of the tool of the present invention, however, fits into the same channel and can provide full surface engagement of the head of the wedge until the tool abuts the tubular frame in which the electrode wires are to be anchored. The wedges are therefore set with precisionand reproducibility. The wedge, in turn, is guided in the groove formed in the tool.

The arcuate nature of the tool, whereby the shank turns away from an imaginary extension of the wire, allows a hammer or the like to strike the shank of the tool without the danger that slipping of the hammer will damage the electrode wire. Furthermore, the groove formed in the tool seats against the wedge which prevents slippage in the direction of impact. The complementary configuration of the rib of the tool and the channel of the corona-discharge electrode and the complementary configuration of the wedge and groove of the tool, together with the substantially complementary inter-fitting of the wedge and the electrode channel ensures substantially all-around engagement of the wedge and confinement thereof against lateral displacement while it is driven into place. It has been found to be advantageous, moreover, to provide the shank of the tool with means for coupling the latter to a pneumatic or electromotive impactor, e.g. a pneumatic or electric hammer. Best results have been obtained with the use of a pneumatic hammer which markedly reduces the stress upon the user.

DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a vertical elevational view of a system for anchoring an electrode in a tubular electrode frame according to the invention, the wedge being hatched for convenience of illustration;

FIG. 2 is a cross-sectional view taken along the line of II II of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line 111 III of FIG. 1;

FIG. 4 is a view taken in the direction of arrow IV of FIG. 1; and

FIG. 5 is a detail view of the system after the wedge has been driven into place, partly broken away.

SPECIFIC DESCRIPTION In FIG. 1 of the drawing, I show a portion of a frame 1 across which a multiplicity of corona-discharge electrode wires are to be spanned in accordance with the practices common in the electrostatic precipitator art. To receive the electrode 3, the upper tubular bar of frame 1 is provided with bores 2 into which the electrode is inserted. The electrode 3 is shown to be a profiled bar of polygonal cross-section and, in the embodiment illustrated, has four sides 4 defining between them the sharp edges 4a which run the length of the electrode wire. The sides 4 are concave outwardly to define channels, one of which has been illustrated at 4b with an axis of curvature located to the left of this channel, as seen in FIG. 2.

A wedge 6 is introduced between the wall of bore 2 and the channel 4b and has a circular profile as best seen in FIG. 2 so that its convex face 6a is substantially complementarily received in the channel 4b. This channel may have a depth which is up to the radius of the wedge 6 and may be between 0.1 R and 1 R where R is the radius of the head of the wedge. The wedge and the channel thus lie in substantially tangential relationship.

The tool which is used to drive the wedge according to the present invention, is represented at 5 and is bent from a rod which may be hardened at least at the upper and lower ends thereof. The rod, which has a circular cross-section shape 50, is bent into an obtuse angle a at the lower one third of the rod, this angle being between 170 and This curved lower end is flattened along its flanks 5b and 5c and has an abutment face 5d adapted to come to rest against the upper surface 2a of the frame 1 when the wedge has been driven fully into the bore 2 (compare FIGS. 1 and 5). As is also best seen in FIG. I, 2 and 3, the lower end of the tool is formed with a groove 7 terminating at the face 5d and substantially complementary to the head of wedge 6 (see FIGS. 1 and 2).

At the other end of the groove, which has an axial depth D equal to the desired height of the wedge above the surface 2a, there is provided an abutment or shoulder 8 which rests against the wedge when the latter is driven into place. The abutment or shoulder 8 forms part of a rib 5e which is complementarily received in the channel 4b (see FIGS. 1 and 3).

At its upper end, the tool is formed with an annular flange or shoulder 9 receivable in a pneumatic hammer which is represented at 10. When the impact force in the direction of arrow A is applied, it has a relatively small component B which is taken up by the wedge and the electrode and a relatively large component C perpendicular to the face 5d and serving to drive the wedge into the bore 2. The process is completed when the surfaces 5d bottoms against the surface 2a.

The improvement described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the invention except as limited by the appended claims.

I claim:

1. A tool for setting a wedge of circular cross section in a corona-electrode frame provided with respective bores each receiving a corona-discharge star-profile electrode wire having arcuately concave flutes comprising a bar having a shank and an end bent arcuately at an obtuse angle to said shank over about one third of the length of said bar, said end being formed with a groove for receiving said wedge and of a circular arcsegmental complementary to that of said wedge, said end having at its extremity a face adapted perpendicular to the axis of said bar at said end and to abut said frame upon driving of said wedge into the respective bore, a rib of circular -segmental profile formed on said bar and receivable in one of said flutes, and an abutment surface at the opposite extremity of said groove parallel to said face and engageable with said wedge for entraining said wedge upon impact displacement of said bar.

2. The tool defined in claim 1, further comprising a pneumatic hammer connected to said shank.

3. The tool defined in claim 1, further comprising an electromotive hammer connected to said shank. 

1. A tool for setting a wedge of circular cross section in a corona-electrode frame provided with respective bores each receiving a corona-discharge star-profile electrode wire having arcuately concave flutes comprising a bar having a shank and an end bent arcuately at an obtuse angle to said shank over about one third of the length of said bar, said end being formed with a groove for receiving said wedge and of a circular arc-segmental complementary to that of said wedge, said end having at its extremity a face adapted perpendicular to the axis of said bar at said end and to abut said frame upon driving of said wedge into the respective bore, a rib of circular -segmental profile formed on said bar and receivable in one of said flutes, and an abutment surface at the opposite extremity of said groove parallel to said face and engageable with said wedge for entraining said wedge upon impact displacement of said bar.
 2. The tool defined in claim 1, further comprising a pneumatic hammer connected to said shank.
 3. The tool defined in claim 1, further comprising an electromotive hammer connected to said shank. 